Patent US3768027A successfully refreshed from Google Patents.
US3768027A
Expired / Lapsed
US
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Fm limiter using single diode
Assignee: Thomas International Corp
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Filing: 1971-08-18
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Granted: 1973-10-23
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Expires: 1991-08-18
Abstract
Abstract A limiter circuit for an FM detector including a diode serially connected in the signal path between the FM signal source and the FM detector. A current source biases the diode into conduction. The limiter conducts low level FM signals without substantial alteration, suppresses low frequency signals, and limits the output when the input reaches a predetermined amplitude.
Inventors
- 👤 Matzek L Tuvker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:55
CPC Classifications
H; H03; H03G; H03G11/00; H03G11/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
An FM limiter for an FM detector, comprising: a source of FM signal subject to undesired positive and negative polarity amplitude variations which exceed a minimum peak level, a diode connected in series between said FM source and said FM detector, and a constant current bias source connected to said diode for rendering it conductive when the amplitude variations are less than said minimum peak level and nonconductive during one polarity when the amplitude variations are greater than said minimum peak level to pass a fractional waveform having a fundamental with a magnitude which approaches a maximum amplitude.
Claim 2
Dependent Claim
98 words
An FM limiter for an FM detector, comprising: a source of FM signal subject to undesired positive and negative polarity amplitude variations which exceed a minimum peak level, a diode connected in series between said FM source and said FM detector, and a constant current bias source connected to said diode for rendering it conductive when the amplitude variations are less than said minimum peak level and nonconductive during one polarity when the amplitude variations are greater than said minimum peak level to pass a fractional waveform having a fundamental with a magnitude which approaches a maximum amplitude.
Claim 3
Dependent Claim
24 words
The FM limiter of claim 1 wherein said bias source includes a constant potential supply serially connected through a bias resistor to the diode.
Claim 4
Dependent Claim
24 words
The FM limiter of claim 1 including a load connected in shunt with the series connection for providing a path for the bias current.
Claim 5
Dependent Claim
40 words
The FM limiter of claim 3 including a capacitor serially connected between the FM source and the diode and having a capacitive reactance at the frequency of the FM signal which is substantially less than the resistance of the load.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |